KR101469434B1 - method for transferring local IP address from SDN to femto cell - Google Patents

Abstract

The present invention relates to a method for transferring a local host IP address to a femtocell in an SDN, in which a femtocell receives an IP address of a local host from an SDN to directly communicate with the local host connected to the SDN. The method for transferring a local host IP address to a femtocell in an SDN of the present invention includes: step (a) receiving an IP address table of an SDN switch controlled local host from an SDN controller when a mobile communication terminal enters, which is performed by a femto base station when the femto base station is connected to the SDN switch and the SDN controller; step (b) determining whether a destination IP address, with which the mobile communication terminal desires to communicate, exists in the IP address table received in the step (a); and step (c) performing, based on a determination result in the step (b), a LIPA by transferring a packet having a destination of the local host to the SDN switch without going through a core network when the destination IP address exists while transferring the packet through the core network when the destination IP address does not exist. In the method, the SDN controller receives the IP address of the local host from the SDN switch, and the SDN switch analyzes an ARP packet between the SDN switch controlled local host to extract the IP address.

Description

Method for transferring local host IP address from SDN to femtocell {method for transferring local IP address from SDN to femto cell}

The present invention relates to a method of transmitting a local host IP address from an SDN to a femtocell, and more particularly, to a femtocell in which an femtocell receives an IP address of its local host from an SDN, To a local host IP address delivery method.

As is well known, a femto cell base station (hereinafter, simply referred to as a 'femto base station') is a very small mobile communication base station connected to a mobile communication core network through a broadband network installed in a house or an office. These femto base stations have various advantages such as expanding indoor coverage, improving call quality, and efficiently providing various wired / wireless convergence services.

In 3GPP LTE (Long Term Evolution), an evolved NodeB (eNB) and a home evolved NodeB (HeNB) have been defined. The eNB is a macro base station that manages a general macro cell and the home eNB is a femto base station that controls a femtocell. That is, 3GPP considers an environment in which a femto base station that can be connected to only a specific user is installed separately from an existing macro base station. At this time, the femto base station may be installed by a user or a provider for the purpose of increasing coverage, increasing capacity, or providing other differentiated services. The service coverage of a femto base station can be considered from a minimum of several meters to a maximum macro service coverage degree.

On the other hand, Software Defined Networking (SDN), which is called software defined networking, is a new structure network or paradigm that can fundamentally solve and solve the structural problems of the current Internet through software, Abstraction, standardized interface, and hardware.

The SDN has a network structure in which the network control function is separated from the physical network having the data transfer function. The control function of the SDN thus separated is the data path on the network switch It should have a function that can function. One such interaction or communication mechanism is the OpenFlow technology, which is a standard interface for communication between a machine with control functions and a networking switch.

According to SDN, control functions, also called controllers, are implemented on separate machines, not switches or routers, which can be PCs or high-performance servers.

On the other hand, in an existing network other than SDN, local hosts have IP addresses and subnets allocated from their own switches. Therefore, when data is transmitted, it is determined whether to make a destination locally or a default gateway gateway can be determined.

However, as described above, unlike the existing network, the SDN switch does not route using the IP address scheme. That is, since the SDN switch does not have the IP address and the MAC address and does not allocate it, You can not decide whether to send the data or the default gateway. As a result, even if the femto base station attempts to communicate with the hosts of the local network connected to the SDN switch, there is no way of knowing the IP address of the host connected to the local network.

10-2014-1244 (Title of the Invention: Network Device and Process for Determining Connection Context for Connection Used for (Local) Offloading) * 10-2012-123496 (Patent Title: Femtocell One-to-Many Packet Delivery) * 10-2010-119349 Disclosed is a method and apparatus for supporting local IP access in a wireless communication network including a femtocell. A method, apparatus, system and computer-readable recording medium for supporting communication between user terminal devices using an open flow (OpenFlow)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a femtocell to a femtocell, which is capable of directly communicating with a local host connected to an SDN, Address delivery method.

In order to accomplish the above object, there is provided a method for transmitting a local host IP address from an SDN to a femtocell in a femto base station in a state in which the femto base station is connected to an SDN switch and an SDN controller, (A) receiving an IP address table of a local host of the SDN switch control from the controller; (B) determining whether a destination IP address for which the mobile communication terminal intends to perform communication exists in the IP address table received in the step (a), and if it is determined in step (b) (C) delivering a packet destined for the local host to the SDN switch through the network without going through the network, while delivering the packet through the core network when the LIPA does not exist.

In the above-described configuration, the SDN controller receives the IP address of the local host from the SDN switch, and the SDN switch analyzes the ARP packet between the local hosts of the self-controlled terminal and extracts the IP address.

The femto base station transmits the attachment information of the mobile communication terminal to the SDN controller before the step (a), and the SDN controller checks whether the mobile communication terminal is a registered subscriber according to the attachment information, The step (b) is performed.

The attaching information is an IMSI of the mobile communication terminal. The SDN controller inquires the subscriber identification number of the registered subscriber in advance and confirms whether the subscriber is a registered subscriber or inquires the subscriber identification number to the mobile communication terminal The mobile communication terminal checks whether the mobile communication terminal is a registered subscriber through a process of confirming whether the subscriber is a registered subscriber.

Wherein the step (a) is performed by a request of the femto base station when the mobile communication terminal enters.

According to the method of transmitting the local host IP address from the SDN to the femtocell according to the present invention, utilizing the local IP address obtained in the ARP operation process between the local hosts even under the SDN network enables the LIPA without any problem in the SDN environment without using the subnet mask. Can be performed.

1 is a sequence chart for explaining a method of transmitting a local host IP address from an SDN to a femtocell of the present invention.
2 is a diagram for explaining a process in which an SDN controller acquires an IP address of a local host of an SDN switch in the present invention;
3 is a diagram for explaining a process in which an SDN controller transmits an IP address of a local host to a femto base station in the present invention.
4 is a diagram for explaining a process in which a femto base station performs LIPA with local hosts according to local host IP information received from an SDN controller in the present invention.

Hereinafter, a preferred embodiment of a local host IP address forwarding method from the SDN to the femtocell of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a sequence chart for explaining a method of transmitting a local host IP address from an SDN to a femtocell according to the present invention. FIG. 2 illustrates a process of acquiring an IP address of a local host of the SDN switch in the present invention. FIG.

As shown in FIG. 2, in the SDN, the SDN controller 40 performing the network control function is separated from the SDN switch 20 serving as the physical network responsible for the data transfer function (data plane) . Here, the SDN controller 40 may be implemented as a PC or a server with high performance, and the SDN switch 20 may be a general router or the like.

In the above-described configuration, the SDN switch 20 is connected to a public data network such as the Internet and has a plurality of local hosts Lh1 and Lh2. The SDN switch 20 is also connected to the femto base station 10 to provide a mobile communication terminal that has entered the femto base station with a LIPA service for the local host of its own jurisdiction.

Next, the femto base station 10 is connected to a core network such as a Mobility Management Entity (MME) through a radio network controller to provide a mobile communication service to the mobile communication terminal. The femto base station 10 may be installed for the purpose of increasing coverage, increasing capacity, or providing other differentiated services by a user or a business entity as described above.

The service coverage of the femto base station 10 can be considered from a minimum of several meters to a maximum macro service coverage degree. Here, the femtocell may be a specific group registered beforehand to access the cell, that is, a closed subscriber group cell or a cell opened to all subscribers. In the embodiment of FIG. 1, it is assumed that the femtocell is a CSG cell . The femto base station 10 may comprise a local serving gateway and a local PDN gateway.

Meanwhile, a local IP access (LIPA) service means a service in which data of a mobile communication terminal is directly transmitted to a data network (or a local IP access network) without passing through a core network. Here, the local IP access network refers to all public data networks that are heterogeneous to the core network, and may be an Internet or a service network that provides a home service.

The SDN switch 20 also analyzes the packet transmitted when the local hosts Lh1 and Lh2 perform an ARP operation to communicate with each other, extracts the IP address of the local host, and transmits the IP address to the SDN controller 40 , Which will be described in more detail in Fig.

As shown in FIG. 1, the SDN switch 20 analyzes packets transmitted when the local hosts Lh1 and Lh2 perform an ARP operation to communicate with each other and stores the IP addresses of the local hosts Lh1 and Lh2 (Step S20), and the SDN controller 40 stores the received IP address of the local host in the IP address table (step S30).

Here, ARP (Address Resolution Protocol) is a protocol used to map an IP address, which is a logical network address, to a physical network address on the network. Where the physical network address is the 48-bit network card address of the Ethernet or Token Ring.

For example, if local host # 1 (Lh1) does not know the physical network address of local host # 2 (Lh2) when it tries to send an IP packet to local host # 2 (Lh2) And transmits an ARP packet having a broadcasting physical network address of 0xFFFFFFFFFFFF on the network. Next, the local host # 2 (Lh2) responds to its own physical network address to the local host # 1 upon receiving an ARP packet whose IP address is the destination. The IP address and the corresponding physical network address information collected in this manner are stored in the form of an IP address table in a memory called an ARP cache of each local host, and then used again when a packet is transmitted.

3 illustrates an example in which the SDN controller transmits the IP address of the local host to the femto base station, in which the mobile communication terminal 50 is connected to the femto base station 10. As shown in FIG. 3, when the mobile communication terminal 50 enters the service area of the femto base station 10 (step S40 in FIG. 1), the femto base station 10 determines whether the femto base station 10 is a registered subscriber The SDN controller 40 transmits the message containing the Attach information of the mobile communication terminal, for example, the International Mobile Subscriber Identity (IMSI), which is the subscriber identification number of the mobile communication terminal used in the LTE system Step S50).

Next, the SDN controller 40 determines whether the terminal is a registered subscriber by receiving the corresponding message (step S60 in FIG. 1). To this end, the SDN controller 40 transmits the identification number (IMSI) The user is registered in advance or at that time, the mobile communication company is inquired as to whether or not the user is a registered subscriber, and step S60 is performed. As a result of the determination in step S60, if it is not a registered subscriber, it is ignored (step S65). On the other hand, if the subscriber is a registered subscriber, the IP address table of the local hosts previously stored is transmitted to the femto base station 10 S70).

4 is a diagram for explaining a process in which a femto base station performs LIPA with local hosts according to local host IP information received from an SDN controller in the present invention. 4, when the destination IP address for which the mobile communication terminal 50 intends to perform communication exists in the IP address table received from the SDN controller 40, that is, the femto base station 10 performs the LIPA (Step S80). If the packet is present, the packet is transmitted to the SDN switch 20 via the local network without going through the core network to perform the LIPA. On the other hand, if the destination IP address does not exist in the IP address table received from the SDN controller 40, the packet is transmitted through the core network (EPC) (step S100 in FIG. 1).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Will be possible. Accordingly, the scope of the present invention should be determined by the following claims.

For example, in the case of an open femto base station providing a service irrespective of whether it is a registered subscriber, steps S50, S60 and S65 in FIG. 1 may be omitted. In this case, the SDN controller may change the local host IP address of the SDN switch jurisdiction, that is, change the contents of the IP address table, or transmit the IP address table in response to the request of the femto base station according to the position of the mobile communication terminal will be.

10: femto base station, 20: SDN switch,
40: SDN controller, 50: mobile communication terminal,
Lh1, Lh2: Local host

Claims (5)

Is performed by the femto base station with the femto base station connected to the SDN switch and the SDN controller,
(A) receiving an IP address table of a local host of the SDN switch from the SDN controller when the mobile communication terminal enters;
(B) determining whether a destination IP address for which the mobile communication terminal intends to perform communication exists in the IP address table received in the step (a); and
As a result of the determination in step (b), if there is a packet, the LIPA is performed by transmitting a packet destined for the local host to the SDN switch without going through the core network. If the packet is not present, And transmitting the local host IP address from the SDN to the femtocell. The method according to claim 1,
The SDN controller receives the IP address of the local host from the SDN switch,
Wherein the SDN switch analyzes an ARP packet between the local hosts of the self-controlled node and extracts the IP address of the ARP packet from the SDN to the femtocell. 3. The method of claim 2,
Before the step (a), the femto base station transmits the attachment information of the mobile communication terminal to the SDN controller,
SDN controller performs step (b) when it is a registered subscriber after confirming whether the mobile communication terminal is a registered subscriber according to the attach information. . The method of claim 3,
The attach information is a subscriber identification number (IMSI) of a mobile communication terminal,
The SDN controller inquires the subscriber identification number of the registered subscriber in advance and confirms whether the subscriber is a registered subscriber or inquires the subscriber identification number to the mobile communication company to confirm whether the subscriber is a registered subscriber, The local host IP address from the SDN to the femtocell. The method according to claim 1,
Wherein the step (a) is performed according to a request from the femto base station when the mobile communication terminal enters the method, wherein the local host IP address is transmitted from the SDN to the femtocell.

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